Overview of Avian Influenza Prevention, Preparedness and Response

Avian influenza (AI) is a contagious viral infection that can affect several species of poultry, such as chicken and turkey, as well as pet and wild birds. AI viruses can be classified into two categories-low pathogenic (LPAI) and high pathogenic (HPAI)-based on the severity of the illness caused in poultry. HPAI viruses typically cause severe illness and mortality, whereas LPAI viruses typically cause little or no clinical signs. Most AI viruses are low pathogenic; however, some subtypes are capable of becoming highly pathogenic. Historically, only the H5 and H7 LPAI virus subtypes are known to have the ability to become highly pathogenic and they are considered notifiable.

The Government of Canada attaches high priority to the threat of AI and is devoting significant resources to prevent the introduction and spread of AI in Canada. The Canadian Food Inspection Agency (CFIA) is at the forefront of that effort.

The CFIA, working with a number of Government of Canada partners, has put in place a series of measures to limit the animal health risks-and associated economic repercussions of outbreaks-posed by AI. In the context of human health, these measures also reduce the potential risk that AI infection in birds will serve as the precursor to a human flu pandemic. International human and animal health authorities agree that efforts to protect human health are best directed at preventing, limiting and eradicating AI outbreaks in domestic poultry.

Prevention and Early Warning

There are a wide range of AI viruses continuously circulating within wild bird populations. The majority of these do not cause serious illness in animals or humans. The first lines of defence against an outbreak of AI in domestic poultry are prevention measures and early warning systems. The CFIA, in collaboration with other Government departments, has put in place safeguards to limit the introduction and spread of AI in Canada's domestic poultry populations.

Surveillance

The Canadian Government uses two different bird surveillance programs to detect AI viruses posing threats to domestic poultry at the earliest possible moment. The first program targets wild birds; the second one focuses on domestic flocks.

Wild Bird Surveillance

The CFIA, Environment Canada, the Public Health Agency of Canada and the Canadian Cooperative Wildlife Health Centre collaborate to conduct an annual survey of AI viruses in wild birds. The survey partners expect to find a variety of AI viruses, most of which commonly circulate in wild birds with little or no impact on their health or the health of other animals. The survey includes sampling of live birds during the spring, summer and fall and continued year-round sampling of dead birds. The survey is intended to provide early detection of highly pathogenic AI in Canada and determine the presence and characteristics of the AI strains in North America's wild bird population.

Survey partners are particularly interested in AI viruses that are or have the potential to become highly pathogenic. These viruses, which include the H5 and H7 subtypes, can cause illness and death in poultry. The highly pathogenic H5N1 AI virus strain currently circulating in Asia, Africa and Europe has demonstrated the ability to affect poultry and wild birds, as well as humans and other mammalian species.

Commercial Bird Surveillance

The CFIA, in collaboration with industry, has designed a commercial bird surveillance program, called the Canadian Notifiable Avian Influenza Surveillance System (CanNAISS), to complement the wild bird survey. Samples are taken from live birds and tested in CFIA accredited labs. This survey helps us develop a better picture of AI viruses that might be circulating in Canadian poultry and can help to identify where breaches of on-farm biosecurity might have occurred and identify courses of corrective action. Additionally, abnormal patterns of flock productivity and mortality would be watched closely.

International Bird Surveillance

Through international cooperation and information sharing, Canada continuously monitors AI developments around the world and adjusts import controls and disease response plans accordingly.

Biosecurity

AI virus can be transmitted directly from bird to bird through secretions and feces, and indirectly through human movement, contaminated feed, water and equipment. In light of the threat and risks associated with AI, increased attention has been drawn to the ongoing need to protect domestic poultry through the effective use of on-farm biosecurity measures. Biosecurity involves maintaining good hygiene practices and limiting exposure to external sources of contamination.

Commercial Flocks

Most poultry and egg production industry associations already have biosecurity guidelines in place for their memberships to reference. The CFIA's role involves promoting best practices and providing technical advice across industry so that all producers are using the most effective measures possible and that these measures are being applied in a uniform fashion across the country.

Other Flocks

The CFIA recognizes that not all poultry and egg production in Canada is done by large producers that are members of industry associations. There are smaller producers who maintain what are commonly called "backyard flocks." The CFIA, in collaboration with the provinces and territories, has implemented an awareness campaign for owners of these types of flocks to inform them of biosecurity best practices and encourage them to take the necessary steps to protect their flocks.

Import Measures for Live Birds

These measures apply to countries which are recognized as being free of highly pathogenic AI in their domestic flocks. Canada continues to prohibit trade in poultry, poultry products and birds with any country until domestic poultry are proven to be free of highly pathogenic AI.

These measures are consistent with guidelines established by the World Organization for Animal Health (OIE) and provide a foundation for safe trade while protecting animal and human health. Canada's import controls were developed in consultation with provincial governments, the Canadian poultry industry and Canada's principal poultry and bird trading partners: the United States and the European Union.

Emergency Preparedness

While it is extremely important to have early warning systems and prevention measures in place to keep AI out of Canada, similar effort must be directed toward being prepared for the possibility of an outbreak. Since 2004, Canada has experienced one high pathogenic AI outbreak and testing has identified many different AI viruses, including H5 subtypes, which were determined to be low pathogenic. During these incidents, many valuable lessons are learned and experience is gained.

Emergency Response Team

The CFIA has a dedicated response team of experts that will be activated in the event of an AI outbreak. This group includes veterinarians, executive management and field staff, will oversee the CFIA's response and coordinate actions with federal, provincial and municipal partners.

Development of Detailed Procedures for Response

Preparedness requires that contingency plans be in place for every activity associated with an outbreak. Among the many detailed plans and procedures, there are plans for: humane and rapid destruction of infected flocks; minimizing the spread of virus; effective disposal of carcasses; movement restrictions on susceptible livestock and products; protecting the health and safety of staff deployed during an AI outbreak, protecting the health of farmers and producers during an AI outbreak, and capturing information in databases for epidemiological analysis of the outbreak.

Avian Influenza scenarios and exercises

The CFIA conducts a number of internal and external exercises to further enhance preparedness for a possible AI outbreak. Internally, the CFIA continues to enhance its ability to respond through ongoing emergency preparedness workshops and training events. Externally, the CFIA participates in exercises with industry as well as other government departments and levels of government to test response to AI in different parts of Canada.

Partnerships with other Government Departments, other levels of Government and External Bodies

The CFIA continues to work closely with other Government departments, other levels of government, the poultry and egg producing industries and the scientific and academic communities, all of which have a focus on AI.

Partnerships with other Federal Government Departments and Agencies

At the Federal level, the CFIA's AI partners include, but are not limited to, Agriculture and Agri-Food Canada, the Department of Foreign Affairs and International Trade, Environment Canada, Health Canada, the Public Health Agency of Canada, Public Safety Canada and the Canada Border Services Agency.

The lead department or agency in the event of an AI outbreak is scenario dependent. If the scenario only involves animal health, then the CFIA will have the lead coordinating role in responding to the threat. If the scenario starts as an animal health issue, and then evolves into a human health issue, then the lead coordinating role would shift to the Public Health Agency of Canada. In the event that AI starts as a human health issue, the Public Health Agency of Canada would assume the lead role in coordinating the response.

The CFIA collaborates with these partner departments on AI and pandemic scenarios on an on-going basis.

Provinces and Territories

The CFIA continues to communicate with its counterparts in the provinces and territories to ensure that information, policies, procedures, strategies, plans and communications products are shared and coordinated.

The CFIA, in collaboration with provincial governments, is continuously reviewing and updating the joint Foreign Animal Disease Emergency Support Agreements, which define the roles and responsibilities of each partner in the case of a disease outbreak. These plans are based on four major disease control principles: rapid detection of newly infected livestock; halting the spread of the disease through movement controls and the rapid destruction of infected livestock; movement controls and surveillance on high risk livestock and proximal livestock; and preventing re-infection through the effective biocontainment of infective material (carcasses, manure and feed).

Industry and Academia

The CFIA has solicited expertise from industry and the scientific and academic communities by striking an Avian Influenza Advisory Group. Representatives help to ensure that CFIA policies and action plans are sound. These consultations are ongoing and continue to provide valuable intelligence that helps to shape the CFIA's overall strategy to combat AI in Canada.

Partnerships with International Bodies

The CFIA collaborates with leading international bodies such as the OIE, the Food and Agriculture Organization and the World Health Organization to share and distribute intelligence, and best practices with regard to combating Avian Influenza. The fight against AI is truly an international effort with many nations, including Canada, providing assistance to other areas of the world where resources may be limited and are needed to help contain the global spread of AI. This effort benefits all nations and serves the best interests of Canada.

The CFIA's National Centre for Foreign Animal Diseases in Winnipeg is recognized by the OIE as an international reference laboratory for AI.

Additional Capacity

It is understood that responding to an AI outbreak will require additional human resources, equipment and facilities. The CFIA determines how much "surge capacity" will be needed to address a specific threat and then develops unique contingency plans to add resources and capacity as needed. This is especially true for AI. Surge capacity planning with regard to AI focuses on the following areas:

Internal Staffing Reserve - ensuring the CFIA has enough staff, back-up staff and staff rotation for the duration of an AI outbreak.

External Staffing Reserve - ensuring that the CFIA has identified trained persons not currently on CFIA staff, but having relevant experience, so that they can be deployed during an AI outbreak, if required.

Equipment - ensuring that the CFIA can, at short notice, acquire and deploy the equipment required to address an outbreak of AI in Canada. This would include, but is not limited to, personal protective equipment for CFIA staff, vehicles, and depopulation equipment for the humane culling of infected animals.

Laboratories - Six provincial laboratories have been CFIA approved for AI sample testing. The CFIA maintains four labs of its own so that it can also conduct AI testing. CFIA lab staff can be mobilized to move closer to an AI outbreak anywhere in Canada.

Communications

The CFIA recognizes that communication is a key component in Canada's national effort to prevent, contain and eliminate AI outbreaks.

The CFIA maintains ongoing and frequent communications with federal and provincial government partners, the animal health community, bird owners, industry, international disease control authorities and, most importantly, the Canadian public. Timely and transparent communication ensures that the most reliable and recent information is available to decision makers, stakeholders and Canadians. The CFIA recognizes that awareness and credible, science-based information are essential components of Canada's AI readiness and response capacity.

Response

In the event of an outbreak of AI in Canada, Canadians can be assured that the CFIA has action plans to guide effective and efficient response operations. These plans draw from previous experience in Canada and abroad, and the most current internationally accepted understanding of AI.

While specific response elements vary based on the virus and infected poultry species, the CFIA's actions generally include movement restriction, disease containment and surveillance components.

Disease Containment

All infected flocks are humanely destroyed, and carcasses are disposed of in an environmentally acceptable fashion. Infected premises are thoroughly cleaned and disinfected before new birds can be introduced. Where highly pathogenic virus is present, flocks in the vicinity of infected premises and those from poultry operations that may have had contact with infected premises are also humanely destroyed and disposed of as a pre-emptive measure.

Surveillance, Quarantine and Segregation

Because each outbreak situation is unique, CFIA responses are flexible and may differ based on a variety of factors. For example, some disease response protocols are species specific. What follows, therefore, is the general approach to surveillance and segregation after an outbreak of AI in domestic poultry has been confirmed.

Quarantines restricting the movement of poultry and poultry products are placed on infected premises, poultry operations located in the vicinity of infected premises and other poultry operations that may have had contact with infected premises. Birds from quarantined premises are tested and monitored for evidence of AI infection

The CFIA may also ask domestic poultry producers to execute a segregation protocol. A segregation protocol seeks to minimize, if not eliminate, potential contact between wild birds and domestic or captive birds in the area after a case of HPAI has been confirmed.

During highly pathogenic avian influenza outbreaks a Control Area is established by Ministerial Order.

Vaccination

Vaccination of birds against AI is not always practical, effective or economical in any given outbreak situation. The CFIA has studied vaccination as a strategy against the spread of AI and has created guidelines around its effective use. Vaccination is certainly one of many strategies that the CFIA may employ during an AI outbreak.